I totally agree about a shut off but a low pressure audiable warning is too long overdue for installation on these older cars.

Twenty dollars and a little time just might save your engine. Otherwise the chain and sprockets plus the tensioning device on the oil pump should be scrutinized and the oil hoses to the heat exchanger changed out if they are of an unknown vintage.

You might get by with a comparison squeeze test of the oil cooler lines in comparison to a new cooler hose. Soft spots or softer overall is rot. Your engine is at risk otherwise to some extent without an audiable device.

In the last couple of weeks there would have perhaps been two engines still functioning properly if they had one. Impossible to say how the person that loaned the car might have reacted though. Any individual that installed the alarm himself would have reacted properly in my opinion though.

As for the integrety of a swaged on replacement. Screw the end into a nut welded or held in a strong vice. give it a serious gradual pull in excess of 100 pounds.

If it comes apart you do not want it in service on your car. It should be a walk in the park for any hydralic shop to do but some still seem to mess it up.